So I am thinking about making my mill motorized so I don't have to use a drill or crank it by hand anymore. I found a great site that lets you input your motor rpm and pulley sizes and spits out the final rpm for you! Thought this might help out a few of you in this forum.
http://www.culvermotor.com/Engineering-Formulas/Pulley-and-RPM-Calculator.html
http://www.culvermotor.com/Engineering-Formulas/Pulley-and-RPM-Calculator.html